HIGH-TEMPERATURE SUPERCONDUCTOR THIN-FILM CHARACTERIZATION BY THE MODULATED OPTICAL REFLECTANCE TECHNIQUE

Measurements are presented of the modulated optical reflectance (MOR) of laser-ablated thin films of YBa2Cu3O7-x having a range of electrica l characteristics. It is found that the room-temperature MOR signal pr ovides a good indication of film quality. There is a strong correlatio n between MOR signal amplitude and a film's normal- and superconductin g-state characteristics. The origins of the MOR signal are discussed a nd it is suggested that it is directly dependent on the characteristic linear temperature dependence of carrier concentration found in high- temperature superconductors. The potential of MOR for superconducting thin-film device inspection is noted.